1. Field of the Invention
The present invention relates to a hammer for an electronic keyboard instrument, which is provided for each key in an electronic keyboard instrument, such as an electronic piano, so as to impart touch weight to each key during key depression.
2. Description of the Related Art
Conventionally, there has been known a hammer for an electronic piano, disclosed in Japanese Laid-Open Patent Publication No. 2006-3495 ([0029], FIGS. 1 and 3 to 5). The hammers are pivotally mounted in association with respective keys on a keyboard chassis supporting a keyboard, and each of the hammers pivotally moves in accordance with depression of an associated one of the keys to thereby impart a predetermined touch weight to the key. As a consequence, the electronic piano can provide a touch feeling closely analogous to that of an acoustic piano.
The hammer is disposed below the associated key, and comprises a metal hammer body extending along the length of the key, and a hammer holder made of a synthetic resin, which is mounted to a side surface of the hammer body and is pivotally supported by the keyboard chassis. The hammer body is formed by a metal plate having a predetermined shape. Specifically, the hammer body has a front end thereof formed in a rearwardly opening C shape in side view, and a rear end thereof formed in a relatively large triangular shape in side view.
On the other hand, the hammer holder is a molded article having a predetermined shape, and is mounted to the front end of the hammer body. Specifically, the hammer holder, when in a state mounted to the hammer body, has a bearing portion formed inside a C-shaped portion of the front end thereof, and a mounting portion to be mounted to the hammer body at respective locations upward and downward of the bearing portion. The mounting portion has a C shape in cross section, which is formed by a body portion formed in a shape corresponding to the shape, in side view, of a portion of the hammer body to which the mounting portion is to be mounted, and collar portions formed along the respective upper and lower edges of the body portion, with an end of each collar portion remote from the body portion being formed with a plurality of clipping pieces for cooperating with the body portion to clip the hammer body in the direction of thickness of the hammer body. Further, the body portion is formed with an engaging portion protruding inside the mounting portion. This engaging portion engages with an engaging hole formed at a predetermined location in the hammer body, whereby displacement and wobbling of the hammer holder with respect to the hammer body are suppressed.
The hammer holder constructed as above is mounted to the hammer body as follows: The body portion of the hammer holder is aligned to the portion of the hammer body to which the body portion is to be mounted, and then pressed toward the hammer body. In this case, a space between the clipping pieces of the hammer holder is opened up in the lateral direction (vertical direction) of the hammer body, and the clipping pieces pass over the respective upper and lower edges of the hammer body whereby they reach the remote side of the hammer body from the body portion, with the hammer body therebetween. Thus, the hammer holder is mounted to the hammer body in a state sandwiching the hammer body in the direction of the thickness of the same between the body portion and the clipping pieces.
As described above, the hammer holder is mounted to the hammer body during assembly of the hammer by opening up the space between the clipping pieces of the hammer holder. Therefore, when the hammer holder is formed of a relatively hard synthetic resin material, a relatively large urging force is required. Further, in the case of disposing of an electronic piano provided with the hammers constructed as above, work for disassembling each of the hammers into the metal hammer body and the hammer holder formed of the synthetic resin material is very complicated and troublesome when a sequence reverse to the above-described sequence is employed. The hammer described above suffers from the problem that work for assembly and disassembly of the hammer comprising the hammer body and the hammer holder is thus complicated and troublesome. Further, there is a fear that a gap is formed between the hammer body and the inner surface of the mounting portion of the hammer holder e.g. due to inevitable size error in manufacturing the hammer body and the hammer holder, causing wobbling and resultant noises during pivotal motion of the hammer performed in accordance with key depression.